Surbiton trunk mains project

Challenges

Since January 2025, our teams have focused on connecting the newly lined pipe into the existing water network. One of the most important tasks was to join it to a larger pipe at Balham Park Road.

We overcame significant engineering challenges during this phase of work, completing the connection in May 2025. 

However, we still needed to fit a special valve and chamber. This was to help control how water flows through the network, directing supply where it's needed. As this valve wasn't in our original plan, it had to be custom made.

Testing and connections

After the main connection activity, we needed to test the new section of pipe. This was completed in July 2025. 

Other works in the area

Other major works on the A23 at Streatham Hill in July 2025 meant we needed to demobilise our works on the A24 until January 2026. This was to reduce disruption and impact on traffic.

Works in 2026

Since January 2026, we have been focusing on connecting the new pipe into the existing water network at the south end. This is near Tooting Broadway station. We have also been carrying out smaller connections along the new pipeline for integration into the water network. This will help with the distribution of water in the area.

We are now working on completing the installation of the valve and chamber at the junction with Balham Park Road. Once complete, our new water main can be commissioned into service. 

Next steps

Our current phase of work started on 30 July at the junction with Balham Park Road. There are temporary traffic lights in place on the A24 during this phase.

This complex scheme began in 2024, in collaboration with Wandsworth Council and Transport for London. Working together, we aim to reduce disruption in the area.

We know this work disrupts the community, and we’re sorry for any trouble it causes.

How you'll be affected

• Temporary 2-way traffic lights are in place on the southbound carriageway from 30 July 2026 
• We are currently working near Balham High Road, with road closures from 30 July to 8 October 2026
• Access will be maintained for residents and businesses via diversion routes
• Bus routes will not be affected
• You may notice an increase in noise and traffic. We’ll do everything we can to keep this to a minimum by installing sound barriers, where necessary

Please see the table below for the updated junction closures of works along the A24. 

Working hours

Our working hours will be Monday to Friday, 7am to 6pm. Weekends 8am to 5pm.